Earth:Mount Cap formation
| Mount Cap Formation Stratigraphic range: Cambrian | |
|---|---|
| Type | Formation |
| Lithology | |
| Primary | Shale, siltstone |
| Other | Sandstone |
| Location | |
| Coordinates | [ ⚑ ] 63°24′23″N 123°12′22″W / 63.40639°N 123.20611°W |
| Region | Northwest Territories |
| Country |  Canada |
  Mount Cap formation (Canada) | |
The Mount Cap Formation is a geologic formation exposed in the Mackenzie Mountains, northern Canada. It was deposited in a shallow shelf setting in the late Early Cambrian,[1] and contains an array of Burgess Shale-type microfossils that have been recovered by acid maceration.[2]
Description
The formation is 100 to 300 metres (330 to 980 ft), and comprises shales, siltstones and sandstones with a high glauconite content.[1] It has been exposed to remarkably little metamorphic activity given its great age; it is dated to the Bonnia–Olenellus Trilobite Zone.[1] This zone lies within the Lower Cambrian Waucoban stage in North America, which is equivalent to the Caerfai in Wales, and thus the Comley of England,[3] and has yet to be formally ratified. Nevertheless, this makes it just younger than the earliest trilobites, and thus the earliest known Burgess Shale-type deposit, though this is disputable when considering the age of Chengjiang County fauna. Its organic-walled fauna, known as the "Little Bear biota", includes both non-mineralized and originally-mineralized taxa, including hyolith and trilobite fragments, anomalocaridid claws, arthropod carapaces and brachiopods.[4]
See also
- List of fossiliferous stratigraphic units in Northwest Territories
References
- ↑ 1.0 1.1 1.2 Butterfield, N. J. (1994). "Burgess Shale-type fossils from a Lower Cambrian shallow-shelf sequence in northwestern Canada". Nature 369 (6480): 477–479. doi:10.1038/369477a0. Bibcode: 1994Natur.369..477B.
- ↑ Harvey, T.; Butterfield, N. (2008). "Sophisticated particle-feeding in a large Early Cambrian crustacean". Nature 452 (7189): 868–871. doi:10.1038/nature06724. PMID 18337723. Bibcode: 2008Natur.452..868H.
- ↑ Siveter, D. J.; Williams, M. (1995). "An early Cambrian assignment for the Caerfai Group of South Wales". Journal of the Geological Society 152 (2): 221–224. doi:10.1144/gsjgs.152.2.0221. Bibcode: 1995JGSoc.152..221S.
- ↑ Butterfield, N. J.; Nicholas, C. J. (1996). "Burgess Shale-Type Preservation of Both Non-Mineralizing and 'Shelly' Cambrian Organisms from the Mackenzie Mountains, Northwestern Canada". Journal of Paleontology 70 (6): 893–899. doi:10.1017/S0022336000038579. Bibcode: 1996JPal...70..893B.
External links
- ((Various Contributors to the Paleobiology Database)). "Fossilworks: Gateway to the Paleobiology Database". http://www.fossilworks.org/cgi-bin/bridge.pl?action=home.
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